Former England captain Michael Vaughan has said the side must stick with Kevin Pietersen as their number three batsman.

Historically, teams have deployed their star batsman at first wicket down to give him the best chance of dictating the course of a match without, if the openers do their job, having necessarily to start against the new ball.

Pietersen has spent most of his England career as a number four batsman but in the final Test against Bangladesh, concluded Wednesday, in Mirpur he made 45 and 74 not out at No 3 as the tourists wrapped up a 2-0 series win.

South Africa-born Pietersen had been struggling for runs following four months out with an Achilles injury and found life tough going against Bangladesh's left-arm spinners in particular.

But he remains England's best batsman and, if fit, is likely to have a key role for the team in a busy year that ends with an Ashes tour of Australia in the lead-up to the 2011 World Cup in Asia.

"He is a class act," said Vaughan. "I liked the way he went up to number three in the last game - and I'd like to see him playing there more consistently, because at number three you can make such a difference.

"There is the chance from number three to dominate and play such an important role," said Vaughan.

"Kevin has that authority, that arrogance about him when he walks out."

Vaughan added: "He's had a number of issues against their left-armers, and when something like that is happening it is always at the back of your mind.

"He was going too far over to the off-side.

"But he made the technical adjustment. Once that has been done, it allows you to go out and play as you can - rather than worry about technique."

Vaughan also praised the performance of stand-in captain Alastair Cook, who led the side after regular skipper Andrew Strauss opted out of the Bangladesh tour.

Cook's tactical ability was queried in some quarters but Vaughan said the 25-year-old, who led England to victory on Wednesday with an unbeaten century, had plenty of time to develop his captaincy skills.

"Since I haven't been captain, it bothers me just how much exposure the captain has to deal with," said Vaughan, who retired last year.

"Alastair Cook has had five games in the job. Give him a chance.

"He made some mistakes but he made some very good decisions too - playing five bowlers in the last Test was a great decision."